Here are the design files for my Z-height sensor board add-on to the RepRapPro Ormerod 3D printer. This board replaces the original IR sensor board used for Z-probing. It has the following advantages over the original:
- It uses modulated infrared light, which makes it much less sensitive to ambient infrared such as is found in sunlight and in incandescent artificial light.
- The sensor board is mounted on the hot end so that the sensor head is in-line with the nozzle in the x-direction. This makes it much less sensitive to variations in head sag.
- The board includes the facility to mount the hot end connectors, eliminating the need for the original 6-pin connector. The new connectors are more reliable and more easily disassembled. In particular, the crimp receptacles can more easily be removed from the connector shell.
- The board can accommodate three Cree LEDs to direct light on the work being printed. Alternatively, it can provide 12V power to an LED strip, or a constant-current supply to external LEDs.
- The board includes provision for thermostatic control of the hot end fan. The fan is turned on when the hot end temperature exceeds approximately 42C, or when the board detects a hot end temperature measurement fault.
- The board can also support an experimental ultrasonic sensor. This allows z-probing to be done anywhere on the bed. Due to variation in the speed of sound with temperature, the ultrasonic sensor is a little temperature-sensitive, but this can be compensated in the firmware.
Work is in progress to adapt the board for capacitive height sensing.
For assembly and usage instructions, please visit: http://miscsolutions.wordpress.com/assembling-and-using-the-eschertech-ormerod-hot-end-board/
I supply bare boards, kits of parts with all SMD components ready-mounted, and fully assembled boards. Contact me via the RepRap Ormerod forum at http://forums.reprap.org/list.php?340 by sending a personal message to dc42.